Regenerated cellulosic fibers, sometimes referred to as semi-synthetics or cellulosics are known in the art. Rayon is made by way of the viscose process which involves reacting cellulose with a concentrated solution of sodium hydroxide to form soda cellulose followed by reacting the soda cellulose with carbon disulfide to form sodium cellulose xanthate. The sodium cellulose xanthate is dissolved in a dilute solution of sodium hydroxide to give a viscose solution which is aged and then extruded through spinerettes into dilute sulfuric acid, which regenerates the cellulose in the form of continuous filaments. Methods of making rayon are reviewed in a 1985 non-wovens symposium paper entitled “The Manufacture, Properties and Uses of Inflated Viscose Rayon Fibers” authored by Woodings et al. Also noted is U.S. Pat. No. 5,124,197 of Bernardin et al.
Cellulose acetate and triacetate fibers are produced by dry spinning cellulose acetate dissolved in acetone and/or a chlorinated hydrocarbon.
Existing commercial processes involving derivatized cellulose are not generally suitable for forming regenerated cellulosic fibers in-situ with other papermaking fibers due to solvent usage and complexity of the processes. Moreover, reactive spinning such as the viscose process and dry solvent spinning are not environmentally friendly processes because of solvent disposal issues and volatile organic vapors.